Via cohesion tension, how does a plant take up water? Water molecules are COHESIVE. This means that they form hydrogen bonds between molecules, and they stick together, forming a chain. This is an unbreakable chain up the xylem to the mesophyll, and, as water evaporates from the mesohpyll on the leaf surface, more water is drawn up, due to the aforementioned cohesive properties.
How does water enter a root hait cell? Water potential is high in the soil, and the water potential in the root hair cell is low, due to the sugars, amino acids, and ions dissolved in it. This creates a waer potential gradient and water moves in by osmosis.
Root cortex - The simplastic pathway means going through the cells. The root hair cell will now have high water pressure, whereas the first cellin the cortex will have low. This means water will move in via osmosis. Then, the next cell will have a lower water potenital then the one the water had just moved into. So water will move into this one via osmosis. This will continue, and whilst this is happening, the water potential of the first few cells has lessened after the water moves on to the cell after, meaning more water can move in.
The Apoplastic way involves moving through the cell wall of the root cortex cells. Due to the cohesive properties of water, it gets pulled along in a unbroken steam, with little resistence, due to the mesh like structure of cellulose having water filled gaps.
Endodermis - Xylem. The water travelling the apoplastic pathway can no longer continue in that pathway, due to the casparian strip, which is waterproof, and so joins the Symplastic pathway, to continue through the endodermis. Endodermal cells actively transport minerals into the xylem, lowering it's water potential, and causing a water potential gradient that allows water to move into the xylem via osmosis.
When the
Tuesday 1 June 2010
Oxygen Disassociation Curves. (:
Aerobic respiration => Glucose => ATP released.
Haemoglobin => Pigement
It enable the bodt to carry round lots of oxygen.
Haemoglobin may vary. Each polypeptide chain (four of them) associates with one haem group, which contains a ferrous Fe2+ ion. This can readily bond to oxygen. It picks up four oxygen molecules.
Haemoglobin without oxygen is blue. Haemoglobin with oxygen is red.
The oxygens leave one at once, not all off of one haemoglobin, and then the next. The first oxygen molecules on all goes, and then the second.
The more oxygen avaliable, the higher the percent saturation with oxygen.
Haemoglobin is in three environments: Tissues, Lungs, Blood Vessels.
In the Tissues and the Lungs, the blood is contained within capillaries that have small pores, meaning the percent saturation can change. In the blood vessels, such as arteries, veins, it cannot change as they are not porus.
Associates with oxygen in the lungs.
Dissociates with oxygen in the tissues.
If there's a high partial pressure (lungs), any drop in it has a small effect in percent saturation, however, if there's a low PP, (tissues) any drop in it has a large effect on percent saturation.
If the curve shifts to the LEFT, there is a greater affinity for oxygen.
If the curve shifts to the RIGHT there is a lower affinity for oxygen.
High affinity => More readily associates with oxygen
Low affinity=> More readily dissociates with oxygen
Haemoglobin => Pigement
It enable the bodt to carry round lots of oxygen.
Haemoglobin may vary. Each polypeptide chain (four of them) associates with one haem group, which contains a ferrous Fe2+ ion. This can readily bond to oxygen. It picks up four oxygen molecules.
Haemoglobin without oxygen is blue. Haemoglobin with oxygen is red.
The oxygens leave one at once, not all off of one haemoglobin, and then the next. The first oxygen molecules on all goes, and then the second.
The more oxygen avaliable, the higher the percent saturation with oxygen.
Haemoglobin is in three environments: Tissues, Lungs, Blood Vessels.
In the Tissues and the Lungs, the blood is contained within capillaries that have small pores, meaning the percent saturation can change. In the blood vessels, such as arteries, veins, it cannot change as they are not porus.
Associates with oxygen in the lungs.
Dissociates with oxygen in the tissues.
If there's a high partial pressure (lungs), any drop in it has a small effect in percent saturation, however, if there's a low PP, (tissues) any drop in it has a large effect on percent saturation.
If the curve shifts to the LEFT, there is a greater affinity for oxygen.
If the curve shifts to the RIGHT there is a lower affinity for oxygen.
High affinity => More readily associates with oxygen
Low affinity=> More readily dissociates with oxygen
Insect respiration
When an organism is large, there is a small surface area to volume ratio, when an organism is small there is a large surface area to volume ratio. Large organism increase surface area to volume ratio by having a more flattened shape, and having specialised exchanged surfaces.
Specialised exchange surfaces are adapted for exchange by that they:
Single celled organisms exchange gas through diffsuin along their bodies.
Insects are terrestrial. They live on land, but water easily evaporates from their surface, leaving them dehydrated. They need to conserve water.
Conserving water opposes the needs of gas exchange: Thin (short diffusion distance), large SA/V ratio, and partially permeable.
Insects have a waterproof covering; a waxxy cuticle all over thier body. Also, they have a large surface area to volume ratio, these are both to prevent water loss, and yet as predicted, they do indeed, combat gas exchange.
So that gas exchage can take place, there is an external network of tubes called Trachae. The trachae divide into smaller tubes, that extend through the tissues, which means air is brought directly to the respiring tissues. At the ends of these smaller tube, Tracheoles, cells are respiring, so the concentration of oxygen is low, which means where the spiracles (pores on hte body) are open, air will diffuse in. Also, as carbon dioxide is in high concentration at the respiring tissues, but not outside of the spiracles, this will diffuse out.
The spiracle's ability to open and close can also control water loss, as when they are closed, water can;t evaportate out.
The diffusion distance needs to be short, so this limits the size of the insect.
Specialised exchange surfaces are adapted for exchange by that they:
- Have a large surface area to volume ratio,
- Thin => short diffusion distance
- Movement of external/internal medium to maintain diffusion gradient,
- Paritally permeable.
Single celled organisms exchange gas through diffsuin along their bodies.
Insects are terrestrial. They live on land, but water easily evaporates from their surface, leaving them dehydrated. They need to conserve water.
Conserving water opposes the needs of gas exchange: Thin (short diffusion distance), large SA/V ratio, and partially permeable.
Insects have a waterproof covering; a waxxy cuticle all over thier body. Also, they have a large surface area to volume ratio, these are both to prevent water loss, and yet as predicted, they do indeed, combat gas exchange.
So that gas exchage can take place, there is an external network of tubes called Trachae. The trachae divide into smaller tubes, that extend through the tissues, which means air is brought directly to the respiring tissues. At the ends of these smaller tube, Tracheoles, cells are respiring, so the concentration of oxygen is low, which means where the spiracles (pores on hte body) are open, air will diffuse in. Also, as carbon dioxide is in high concentration at the respiring tissues, but not outside of the spiracles, this will diffuse out.
The spiracle's ability to open and close can also control water loss, as when they are closed, water can;t evaportate out.
The diffusion distance needs to be short, so this limits the size of the insect.
Tissue Fluid
Tissue Fluid - watery liquid that contains glucose, animo acids, fatty acids, salts, and oxygen. The blood flows along through the body and eventually reaches a capillaries are a lot more narrow then arteries, so the Hydrostatic Pressure increases. Because the hydrostatic pressure has increase water is forced out, leaving the proteins, and this lowers the water potential of the blood, which then pulls the water back in, via osmostic pressure.
Is this right? If anyone could correct me, that'd be great, I really do not understand tissue fluid.
What's with lymph nodes?
(:
Waaaaaaaaaaaaaaaaaaaait, . Got it!
I just had to recap.
So right.
When blood reaches the capillaries, the diameter is a lot less, so this creates hydrostatic pressure. This hydrostatic pressure forces fluid out of the capillary. However because of the new hydrostatic pressure outside of the capillaires, and the low osmotic pressure in the capillaires, due to the plasma proteins, water moves back in.
Is this right? If anyone could correct me, that'd be great, I really do not understand tissue fluid.
What's with lymph nodes?
(:
Waaaaaaaaaaaaaaaaaaaait, . Got it!
I just had to recap.
So right.
When blood reaches the capillaries, the diameter is a lot less, so this creates hydrostatic pressure. This hydrostatic pressure forces fluid out of the capillary. However because of the new hydrostatic pressure outside of the capillaires, and the low osmotic pressure in the capillaires, due to the plasma proteins, water moves back in.
DNA
Function of DNA - Hereditary material used to pass genetic material from generation to generation, and cell to cell.
Three basic components:
Deoxyribose
Phosphate Group
Nitrogenous Base.
Bases: Cytosine always pairs with Guanine, Thymine always pairs with Adenine. Guanine and Adenine are longer molecules then Cytosine and Thymine. If they Guanine paired with adenine, the rung would be to long, and if Cytosine and Thymine paired, it'd be too short, as the distance between the two strands in a DNA molecule is constant, and thsi would not fit this pattern.
Triplet code: Three bases code for one amino acid, amino acids join together, and this forms a polypeptide chain. Polypeptides link together to form a protein. Therefore, the triplet code of animo acids are responsible for which proteins are syntheisised, since, a different combination of bases, makes a different amino acid.
Three basic components:
Deoxyribose
Phosphate Group
Nitrogenous Base.
Bases: Cytosine always pairs with Guanine, Thymine always pairs with Adenine. Guanine and Adenine are longer molecules then Cytosine and Thymine. If they Guanine paired with adenine, the rung would be to long, and if Cytosine and Thymine paired, it'd be too short, as the distance between the two strands in a DNA molecule is constant, and thsi would not fit this pattern.
Triplet code: Three bases code for one amino acid, amino acids join together, and this forms a polypeptide chain. Polypeptides link together to form a protein. Therefore, the triplet code of animo acids are responsible for which proteins are syntheisised, since, a different combination of bases, makes a different amino acid.
Variation
Genetic variation is incareased by mutation, fusion of gametes, and meiosis. Mutation introduces new alleles, that have not been present in past generations. Duting meiosis, a mix of genetic material is given, and all gametes produced are different. The fusion of gametes increases genetic diversity by the ofsrping inheriting different alleles from either parent's gametes.
In asexually reproducing organisms the only way of increasing genetic variation is via mutation, as the gametes are not from two different parents.
Sampling buas and chance can affect how representative a sample is. It can be prevented by using random sampling, a computer to generate it.
In asexually reproducing organisms the only way of increasing genetic variation is via mutation, as the gametes are not from two different parents.
Sampling buas and chance can affect how representative a sample is. It can be prevented by using random sampling, a computer to generate it.
Random chem notes.
Hess' Law: No metter which pathway is taken in a reaction the enthalpy change remains the same.
If a catalyst is hot, more particles exceed the activation energy.
Aldehyde, Ketone = Functional group isomerism.
Initiation: Cl-Cl => 2Cl*
Propegation 1: Cl* + CH4 => HCl + CH3*
Propegation 2: CH3* + Cl2 => CH3Cl + Cl*
Termination 1: Cl* + Cl* => Cl2
Termination 2: CH3* + CH3* => C2H6
Termination 3: CH3*+Cl* => CH3Cl
Sulphates get more soluble as you go down the group, Hydroxides get less soluble as you go down the group. (Group 2)
If a catalyst is hot, more particles exceed the activation energy.
Aldehyde, Ketone = Functional group isomerism.
Initiation: Cl-Cl => 2Cl*
Propegation 1: Cl* + CH4 => HCl + CH3*
Propegation 2: CH3* + Cl2 => CH3Cl + Cl*
Termination 1: Cl* + Cl* => Cl2
Termination 2: CH3* + CH3* => C2H6
Termination 3: CH3*+Cl* => CH3Cl
Sulphates get more soluble as you go down the group, Hydroxides get less soluble as you go down the group. (Group 2)
Species Diversity and all that stuffs.
Species, the number of different species and the amount of inidivduals within that species within a community.
Counting a species is the simplest way of measuring diversity, the problem is, using this method, the number of indivduals aren't taken into account.
Standard Deviation takes into account both the number of speicies, and the amount of indiviuals within that species.
If it is a high diversity, it is assumed that there is a stable community, and the living community is dominant, whereas, with low diversity, the community is unstable, and environmental conditions dominate.
We can asess Biodiversity Index (doing that standard deviation thingy.), by comparing between different habitats, asessing the affect of environment change on the biodiversity index of a community of organisms found in a particular habitat. From this, you can asess how stable or resistant they are to envionmental change. The greater the diversity, the greater the chance of a species being able to adapt to environment change.
Counting a species is the simplest way of measuring diversity, the problem is, using this method, the number of indivduals aren't taken into account.
Standard Deviation takes into account both the number of speicies, and the amount of indiviuals within that species.
If it is a high diversity, it is assumed that there is a stable community, and the living community is dominant, whereas, with low diversity, the community is unstable, and environmental conditions dominate.
We can asess Biodiversity Index (doing that standard deviation thingy.), by comparing between different habitats, asessing the affect of environment change on the biodiversity index of a community of organisms found in a particular habitat. From this, you can asess how stable or resistant they are to envionmental change. The greater the diversity, the greater the chance of a species being able to adapt to environment change.
Alcohols.
Primary: oxidises into an Aldehyde. It can be oxidised once again to form a Carboxylic acid. Secondary alcohols can be oxidised into a Ketone. The gemeral formula for an alcohol is CnH2n+1OH
The reagents for these reactions are Dilute Sulphuric acid, and Potassium Dichromate.
To identifiy whether an alcohol is primary or secondary, after distilling, you can either use Fehling's, which can oxidise an Aldehyde to give a brick red precipitate, but you get nothing from a ketone. You can also use Tollen's Silver Mirror, in which, it oxidises the Aldehyde to give a silver mirror precipitate, but again, does nothing to the ketone, as they cannot be further oxidised, whereas aldehydes can, to Carboxylic acids.
Ethanol is produced by fermentation. The carbohydrates in plants are broken into sugar, and then converted by yeast enzymes into ethanol.
C6H12O6 => 2C2H5OH + 2CO
35 degrees. Air is kept out to prevent further oxidation.
It costs less to grow a plant then to mine, and it is carbon neutral.
Biofuel: A fuel made from a renewable resource.
Carbon Neutral: As much CO2 that is absorbed from the air is given out.
The reagents for these reactions are Dilute Sulphuric acid, and Potassium Dichromate.
To identifiy whether an alcohol is primary or secondary, after distilling, you can either use Fehling's, which can oxidise an Aldehyde to give a brick red precipitate, but you get nothing from a ketone. You can also use Tollen's Silver Mirror, in which, it oxidises the Aldehyde to give a silver mirror precipitate, but again, does nothing to the ketone, as they cannot be further oxidised, whereas aldehydes can, to Carboxylic acids.
Ethanol is produced by fermentation. The carbohydrates in plants are broken into sugar, and then converted by yeast enzymes into ethanol.
C6H12O6 => 2C2H5OH + 2CO
35 degrees. Air is kept out to prevent further oxidation.
It costs less to grow a plant then to mine, and it is carbon neutral.
Biofuel: A fuel made from a renewable resource.
Carbon Neutral: As much CO2 that is absorbed from the air is given out.
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